The present invention pertains to a vacuum treatment system to be used to apply thin, hard layers to substrates. A vacuum treatment system of this kind is composed of a transfer chamber and several treatment chambers allocated to it, such that the substrates to be coated can be inserted into or removed from the treatment chambers by means of a handling device located in the transfer chamber.
For coating of substrates by a coating method proceeding under low-pressure conditions, differing types of systems are known which are designed in accordance with the required treatment stations for the substrates. Depending on the desired coating method, e.g., a sputtering method or a vapor-coating method, and depending on the coating system to be applied onto the substrate, differing types of vacuum treatment systems are used. For example, coating systems consisting of several single layers are produced on the substrate by passing the substrate in sequence through individual coating stations, where in each coating station, a specific, single layer is deposited onto the substrate. Additional treatment stations are needed when the substrate is additionally to be subjected to heat treatment, or if the substrate surface is to be subjected to a preceding or subsequent plasma etching process. The configuration of the single treatment stations is established in a known manner either in cluster formation or as an inline system. When using the so-called inline system, the single treatment stations are arranged one behind the other and the substrate is transported successively through these treatment stations to implement the individual treatment steps. These systems have the advantage that they can be easily integrated into the overall process, either upstream or downstream from the vacuum treatment.
In the known cluster systems, the individual treatment chambers are positioned essentially peripherally to the central handling chamber in which a handling device is provided, by means of which the substrates are transported between the individual treatment chambers.
The essential advantage of cluster systems consists in the fact that they are of compact, space-saving design. One disadvantage of these cluster vacuum treatment systems is that the substrates to be treated can only be operated in a so-called batch mode. A continuous operation, like that possible in inline vacuum treatment systems, is usually not possible for cluster systems. For example, in the cluster system, a minimum number of treated substrates is enclosed in one of the treatment stations and after completed processing, all substrates are transported together from the cluster vacuum system.
An object of the present invention is to create a vacuum treatment system by means of which it is possible to process substrates by vacuum processes, where the process sequence can be integrated advantageously into existing production lines and a space-saving design will be obtained.
Another object of the present invention is to provide a method for coating of workpieces in this vacuum treatment system.